Cellular Flashcards
Why is there different sections in the cell for reactions?
Many of the intra-cellular reactions are incompatible
What is one way that the cell separates the various reactions?
compartmentalization in membrane bound organelles
Since most proteins are hydrophobic, how do the cross the membranes?
Vesicle transporters
Membrane Translocation proteins
Pore - nuclear pores
What are the two main protein trafficking pathways?
Secretory Pathway
Default Cyctosolic Pathway
What are the potential final destinations of proteins from the secretory pathway?
Outside the Cell
Cell Membrane
Lysosomes
What are the potential final destinations of the proteins from Default Cyctocolic Pathway?
Cyctosol
Nucleus
Mitochondria
Perioxsomes
If a protein is of the secretory pathway, what will it pass through?
Rough Endoplasmic Reticulum and Golgi Apparatus
Where can proteins be synthesised?
Cytosol
Mitrochondria
Rough Endoplasmic Reticulum
What determines if a protein is transferred to the RER and where is it located on the protein?
Signal Peptide on the N-terminal of the peptide chain (16-20 amino acids)
What binds to the Signal Sequence on the peptide chain to allow it to be recognised by the proteins on the membrane of the RER?
Signal Recognition Particle
When the Signal Recognition Particle is stimulated it opens a channel to allow enter for the Peptide with the Signal Peptide?
Translocoon
What cleaves the Signal Peptide?
Signal Peptidase
What are the three parts of the Golgi Apparatus?
Cis Cisternae, Medial &s Trans Cisternae, Trans Golgi Network
As the peptide chain passes through the Golgi Apparatus it fuses with vesicles and passes through getting further post-transnational modification. What is this called?
Cis Maturation Model
What post transnational modification occurs in the Golgi apparatus?
Phosphorylation - alters protein activity
Acetlyisation - alters Histone/ Gene activity
Ubiqutatition - degradation
Farnelysation - Targets proteins to the cell membrane and Ras Activity
What is added to keep a protein stuck in the cell membrane?
Stop Translocation
From the default cytosolic pathway, what is added to send the protein to the nucleus?
Nucleus Localisation Signal
What does nuclear bound proteins enter into the nucleus via?
Importin via Importin receptors
What Junction disorder leads to Vonwinkel Syndrome?
GAP junctions
What type of junction is involved in cell to ECM conenction?
Focal Adhesion
What determines the tertiary structure of proteins?
Interactions of the side chain functional groups. including:
- disulfide bonds
- hydrogen bonds
- salt bridges
What is the quaternary structure of proteins?
Mutliple sub unit proteins (groups of peptide chains) come together to form a larger molecule through covalent and non-covalent bonds.
What factors leave mitochondrial DNA most susceptible to mutations?
Highly oxidative reactions taking place inside it
Lack of histones around the DNA
What is it called when thyamine undergoes dimerisation?
Cylobutulythiamine
What is homologous DNA repair?
This is where there has been a double stranded break and the DNA is repaired by using a sister chromotid to make the complimentary strand from - which will return to the damaged chromotid and will then be used to fix the other damaged strand
What can non homologous DNA repair lead to?
Translocation of chromosomes
What is the term used when more than one condon can be used to code for the same amino acid?
why is this important?
Degeneracy
it allows for some mutations to take place
What is the amino acid acceptation to degeneracy? and what does it do?
Methionine is non-degeneracy.
codes for starting point of protein synthesis
When there is a single amino acid change which leads to a similar protein, what is this called?
Conservative amino acid substitute
What does the ribosome scan for in order to carry out translation of the mRNA?
Kozak sequence. this informs it that the next AUG (methionine) is where to start translation
